Social

Deus Ex Human Revolution is not a first-person shooter. This is important so let's repeat that -- Deus Ex Human Revolution is not a first-person shooter.

While there are instances of combat, you will find the odds heavily favor a sneaky surprise attack on the unwary, given the damage ratings of the weapons and the availability to cloak, snipe, or get the drop on enemies using Adam's takedown.

For the most part, you will find that talking to neutral and friendly NPCs work more to your advantage than most. In some cases (e.g., an early example would be Zeke Sanders), you can even talk an enemy into leaving combat and leaving altogether.

The C.A.S.I.E. conversation augmentation dramatically improves Adam's ability to gauge people's intentions; however, it is only necessary if you are going after the Ladies Man extra task. However, having it available means you can talk your way past many more situations that would have devolved into combat.

Aside from Ladies Man, there are only about a few conversations in Deus Ex Human Revolution which require you to make the correct first dialogue choice to earn the achievement/trophy (otherwise, let 'er rip), and you do not need the C.A.S.I.E. augmentation to pick the correct response.